Overview:This news brief from November 2009 focuses on how changes in atmospheric chemistry may have factored into the evolution of life on Earth—specifically, life’s quadrillion-fold growth spurt from microscopic bacteria to organisms the size of the blue whale.

Author/Source:UC Museum of Paleontology

Grade level:13-16

Time:30 minutes

Teaching tips:This article includes a set of discussion and extension questions for use in class, as well as a video podcast. It also includes hints about related lessons that might be used in conjunction with this one. Get more tips for using Evo in the News articles in your classroom.